The UNESCO website just started showing 2 more TWHS from Azerbaijan, which had been submitted last year:
Prehistoric sites of the Azykh and Taghlar caves 23/08/2021 (also returned to Azeri control in 2020)
Khudafarin Bridges and related sites 15/07/2021 ("Azerbaijan reestablished control over the villages on 18 October 2020 during the 2020 Nagorno-Karabakh war.")

I'm guessing this is more a political statement than anything else?

Some points of possible interest on these bridges
a. There is a "complete" (i.e "crossable") 15 arch bridge and a partially destroyed 11 arch one. Google Maps clearly shows that the 15 arch bridge sits astride the Azeri-Iranian frontier.(The coordinates for our T List maps are 39.150856, 46.940355 ) Any nomination would surely need to be a joint one - but, apparently, not for a T List entry. In July 22 Iran was said to be "actively" discussing the "reconstruction" of the 15 arch bridge with Azerbaijan.
b. The 11 arch bridge destruction was carried out in the 1930s by the USSR, though one report states that it was a "joint USSR/Iranian decision" to cut ties between N and S Azerbaijan (how true??). A reminder that, in ethnic terms, "Azerbaijan" is divided between Azerbaijan and Iran, having been "Persian" until split during the series of Russo-Persian wars . Indeed the international frontier along the Aras river which the bridge crosses was only established in 1828. Whilst both contries are Shia, their post USSR relationships have been up and down and, currently, are "difficult" - it would be interesting to see if any joint cooperation could be established on this matter!
c. I have come across this report from 10 Sept 2022 of a visit to the bridges by "Famous worldwide travelers" - No, not Els, but a group led by Charles Veley of "Most Travelled People" fame (infamy?). It seems that Azerbaijan is aiming to present the liberated area as a "Dark Tourism" destination - presumably showcasing the "destruction" of Azeri culture in the area during the Armenian occupation?

I just found out that the component 'Khanbulan' was not inscribed as part of the extension of the Hyrcan Forests (same for 2 locations in Iran).
See this decision https://whc.unesco.org/en/decisions/8386/ and the map on the UNESCO website that shows 17 locations.

I think Clyde and I need to have a second look at where we went again...

OMG, I just realized I can fly for fairly little money from my home airport to Baku next year. Considering a 7 day trip plus two travel days, and would stay in Baku to do day trips from there. Compared to Armenia group day tours seem to be rather expensive. Would that be the way to go for a solo traveler or is renting a car a better value for money? Not considering hitchhiking or minibuses due to limited time.

Any comments on weather in the second half of April?

Any must does from Baku? Totally interested in volcanism and also mud volcanoes, the huge and ugly oil development in the Caspian Sea (likely not accessible), archaeology, history, otherwise cool geology.

Rental cars and gas prices are super cheap in Azerbaijan; after all its economy is based on gas. You will see from all the fancy tall buildings as you come from the airport into town it all came from gas money. Driving around the inner town area can be a little more demanding and when I went (err 2017?) Google map wasn't available - maybe it is now or just use alternatives to navigate.
You want to do half a day for the Baku old town, well basically a few hours is enough if you can fit that into your schedule.
You need a day for the mud volcano area. You can easily drive on your own although having a guide is helpful, maybe hire one just for coming along? The hotels would know this kind of thing. If you don't have a guide it won't be a big deal though.
Baku is still a little chilly in April so a warm jacket is required.

Thanks a lot Zoe! I'm so curious to see the other side of the Am/Az conflict. I don't mean this in a sensationalist kind of way, but really: interested in the people living there. I was surely pretty impressed from driving along the Az-border in Armenia last weak. Yeah, if everything fails with google maps I can download a routable map for my handheld gps and use that. I probably walked a total of 30-35km through Yerevan, and there was so much interesting stuff everywhere. So I'd probably also reserve 2-2.5 days for Baku and the rest for just being out and about in whatever way works out. Still need to do some research on what's easily accessible in mid April and what less so due to remaining snow.

Ateshgah Temple seems to be the next one in line to be nominated by Azerbaijan:
https://www.azernews.az/culture/233338.html

Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan working on a nomination for the Caspian Corridor of the Great Silk Road
https://www.azernews.az/culture/234905.html